When processing semiconductor wafers in processing tools, the processing tool is adapted to and optimized for the size of the wafer to be processed. The size of the wafers are standardized in a limited number of discrete sizes where there has been a tendency towards increasing size in the past decades in order to increase the production efficiency. The three most recently introduced wafer sizes are 150 mm, 200-mm and 300-mm diameter.
A given wafer fabrication facility will normally be configured for handling one wafer size. However, in R&D, pilot production or implementation of a new technology in production, there is a need for tools that can process multiple wafer sizes alternatingly or that can easily be reconfigured for handling different wafer sizes. In the past, when using open cassettes that hold the wafers, this was not a major issue. A wafer handling device can easily be configured so that it can handle wafers of different sizes from/to their respective open cassettes. However, the use of the closed FOUP cassettes for 300-mm wafers requires specific features in the wafer handling and cassette handling system that do not allow handling 200-mm open cassettes alternatingly in the same system.
Accordingly, a need exists for a system capable of handling multiple sizes of substrates in a state-of-the-art facility.